Characterization of Carbon-Contaminated B4C-Coated Optics after Chemically Selective Cleaning with Low-Pressure RF Plasma

Boron carbide (B4C) is one of the few materials that is expected to be mostly resilient with respect to the extremely high brilliance of the photon beam generated by free electron lasers (FELs) and is thus of considerable interest for optical applications in this field. However, as in the case of many other optics operated at modern light source facilities, B4C-coated optics are subject to ubiquitous carbon contaminations. These contaminations represent a serious issue for the operation of high performance FEL beamlines due to severe reduction of photon flux, beam coherence, creation of destructive interference, and scattering losses. A variety of B4C cleaning technologies were developed at different laboratories with varying success. We present a study regarding the low-pressure RF plasma cleaning of carbon contaminated B4C test samples via inductively coupled O2/Ar, H2/Ar, and pure O2 RF plasma produced following previous studies using the same IBSS GV10x downstream plasma source. Results regarding the chemistry, morphology as well as other aspects of the B4C optical coating before and after the plasma cleaning are reported. We conclude from these comparative plasma processes that pure O2 feedstock plasma only exhibits the required chemical selectivity for maintaining the integrity of the B4C optical coating.Comment: 27 pages, 15 figure

Low-pressure RF remote plasma cleaning of carbon-contaminated B4C-coated optics

Altres ajuts: the research by HMF is supported by funding from the "Generalitat de Catalunya, Departament d'Empresa i Coneixement" within the "Doctorats Industrials" program (dossier no. 2014 DI 037)Boron carbide (BC)-due to its exceptional mechanical properties-is one of the few existing materials that can withstand the extremely high brilliance of the photon beam from free electron lasers (FELs) and is thus of considerable interest for optical applications in this field. However, as in the case of many other optics operated at modern accelerator-, plasma-, or laser-based light source facilities, BC-coated optics are subject to ubiquitous carbon contaminations. These contaminations-that are presumably produced via cracking of CH and CO molecules by photoelectrons emitted from the optical components-represent a serious issue for the operation of the pertinent high performance beamlines due to a severe reduction of photon flux and beam coherence, not necessarily restricted to the photon energy range of the carbon K-edge. Thus, a variety of BC cleaning technologies have been developed at different laboratories with varying success [1]. Here, we present a study regarding the low-pressure RF plasma cleaning of a series of carbon-contaminated BC test samples via an inductively coupled O/Ar and Ar/H remote RF plasma produced using the IBSS GV10x plasma source following previous studies using the same RF plasma source [2, 3]. Results regarding the chemistry, morphology as well as other aspects of the BC optical coatings and surfaces before and after the plasma cleaning process are reported

Hematocrit: another important factor in systemic neonatal cardiovascular adaptation

Background: Global cardiovascular adaptation of normal healthy term newborns is rarely studied from a multiorgan and hematological point of view. Aims: To evaluate comprehensive neonatal cardiovascular adaptation during the first days of life with echocardiography and renal-cerebral echo color-Doppler and to correlate it with hematocrit (Ht) changes. Study design: A prospective observational study was conducted on 35 healthy term neonates with a mean ± SD gestational age and birth weight of 39.5 ± 1.1 weeks and 3,400 ± 330 g, respectively. All infants underwent serial echocardiograms at 15 ± 4 hours (day 1) and 72 ± 4 hours (day 3) of age. At the same time, cerebral and renal Doppler parameters were acquired and Ht was sampled. Results: The weight and Ht declined by 220 g (189-251) and 8.1% (6.7-9.5), respectively. Systolic and diastolic diameters of the right ventricle and diastolic left ventricle posterior wall thickness showed a reduction, while the diastolic diameter of the left ventricle showed a small increase. The Doppler cardiac evaluation showed an increase in the mitral E/A ratio and pulmonary acceleration time, a reduction of late transmitral flow peak velocity, aortic peak systolic velocity (PSV), aortic peak systolic pressure gradient, aortic velocity-time integral, aortic mean pressure gradient and pulmonary mean acceleration. We also found a reduction of cerebral resistance parameters and an increase in PSV, end-diastolic velocity, and time-averaged velocity. Other measured parameters remained unchanged. Conclusion: Systemic cardiovascular evaluation about changes in Ht is an essential approach to study newborns, especially during the first days of life when Ht shows a significant decrease. Knowledge of the laws of physics related to the effect of Ht changes on vascular parameters is another important factor in understanding the pathophysiology of neonatal disease states. Further studies are useful to help physicians make evidence-based decisions in the management of newborns in Neonatal Intensive Care Units (NICUs)

Intramural esophagic hematoma secondary to coumarinic anticoagulation: a case report

Esophagic Intramural Hematoma is an uncommon clinical condition, with a prognosis which is essentially benign. On most cases, a predisposing or precipitating factor may be seen, with the most common ones being the history of esophagic instrumentation, food impactations and thrombocytopenia. In the following manuscript, the authors present the case of a 54-years-old male with history of valve replacement surgery, who was treated at the Clinica Cardiovascular (Medellin, Colombia), with a clinical case of Intramural Esophagic Hematoma that was later confirmed to be due to a Coumarinic overanticoagulation. On this case, it is evidenced that Intramural Esophagic Hematoma is an unrecognized complication of Courmarinic anticoagulation therapy

Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer

Body composition in male elite athletes, comparison of bioelectrical impedance spectroscopy with dual energy X-ray absorptiometry

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare body composition results from bioelectrical spectroscopy (BIS) with results from dual energy X-ray absorptiometry (DXA) in a population of male elite athletes. Body composition was assessed using DXA (Lunar Prodigy, GE Lunar Corp., Madison, USA) and BIS (Hydra 4200, Xitron Technologies Inc, San Diego, California, USA) at the same occasion. Agreement between methods was assessed using paired t-tests and agreement-plots.</p> <p>Results</p> <p>Thirty-three male elite athletes (soccer and ice hockey) were included in the study. The results showed that BIS underestimates the proportion of fat mass by 4.6% points in the ice hockey players. In soccer players the BIS resulted in a lower mean fat mass by 1.1% points. Agreement between the methods at the individual level was highly variable.</p> <p>Conclusion</p> <p>Body composition results assessed by BIS in elite athletes should be interpreted with caution, especially in individual subjects. BIS may present values of fat mass that is either higher or lower than fat mass assessed by DXA, independent of true fat content of the individual.</p

Does an extensive diagnostic workup for upfront resectable pancreatic cancer result in a delay which affects survival? Results from an international multicentre study

Backgrounds/Aims: Pancreatoduodenectomy (PD) is recommended in fit patients with a carcinoma (PDAC) of the pancreatic head, and a delayed resection may affect survival. This study aimed to correlate the time from staging to PD with long-term survival, and study the impact of preoperative investigations (if any) on the timing of surgery. // Methods: Data were extracted from the Recurrence After Whipple’s (RAW) study, a multicentre retrospective study of PD outcomes. Only PDAC patients who underwent an upfront resection were included. Patients who received neoadjuvant chemo-/radiotherapy were excluded. Group A (PD within 28 days of most recent preoperative computed tomography [CT]) was compared to group B (> 28 days). // Results: A total of 595 patents were included. Compared to group A (median CT-PD time: 12.5 days, interquartile range: 6–21), group B (49 days, 39–64.5) had similar one-year survival (73% vs. 75%, p = 0.6), five-year survival (23% vs. 21%, p = 0.6) and median time-todeath (17 vs. 18 months, p = 0.8). Staging laparoscopy (43 vs. 29.5 days, p = 0.009) and preoperative biliary stenting (39 vs. 20 days, p 0.99) and endoscopic ultrasonography (28 vs. 32 days, p > 0.99) were not. // Conclusions: Although a treatment delay may give rise to patient anxiety, our findings would suggest this does not correlate with worse survival. A delay may be necessary to obtain further information and minimize the number of PD patients diagnosed with early disease recurrence

Lipid profiling and oil properties of Camelina sativa seeds engineered to enhance the production of saturated and omega-7 fatty acids

14 Páginas.-- 7 Figuras.-- 3 TablasCamelina sativa is one of the preferred oil crops in plant biotechnology due to its agronomic performance, the quality of its oil and the ease with which it can be transformed. Oils with high levels of saturated fatty acids are in demand for structured lipid elaboration, whereas ω-7 fatty acids like palmitoleic or asclepic acids are of interest for other applications, such as in oleochemistry and biolubricant production. Several strategies have been followed to increase the levels of saturated and ω-7 fatty acids in the camelina plant in this work, including silencing the β-ketoacyl-ACP synthase II (CsKASII) condensing enzyme responsible for the elongation of palmitate to stearate, the expression of exogenous thioesterases, and the overexpression of the endogenous stearoyl-ACP desaturase. The silencing of CsKASII produces an important increase in palmitate in the oil seed, whereas the expression of different alleles of sunflower FatA thioesterases favors the accumulation of both palmitate and stearate. The increase in intraplastidial desaturase activity through CsSAD co-expression forced the desaturation of palmitate, inducing the accumulation of important amounts of ω-7 fatty acids. The phenotypes of the different transformants produced were characterized by profiling the different glycerolipid classes accumulated in their seeds. These oils displayed altered physical properties that were investigated by differential calorimetry studies.We are grateful to Professor Edgar B. Cahoon of the University of Nebraska for providing us with the hpKASII hairpin construct used in this work, as well as some transformation vectors and cloning systems used in this project. We also appreciate the help and knowledge that he gave us to carry out this work. This work was funded by Spanish Ministerio de Ciencia e Innovación and ERDF through the grant AGL2017-83449-R.Peer reviewe